Conventional phone ringing tone alarms form a warbler tone by making a connection between two or more different frequencies at a constant speed. Said frequency values have usually been so arranged that one ringing tone only is permitted. However, in microprocessor-based phones various waveforms can be synthesized with the aid of suitable programming. A user is now able to select one waveform out of a small number of various combinations.
Patent application GB-2,183,423 discloses a system for generating a phone ringing tone for use in a subscriber means of the phone, or equivalent, comprising a ringing tone generation circuit connected to a microprocessor to control the ringing tone generation circuit by controlling the output gate connected to the input of the circuit up and down at a speed equivalent to the desired ringing tone frequency. The control of the output gate is so implemented that the on and off states are generated according to a given configuration from the ringing tone, and the parameters affecting the control of the ringing tone output are programmed into the microprocessor from the phone keyboard or equivalent, whereby the user is able to supply the frequency of the ringing tone he/she desires, or other tone of the sound. The microprocessor controls the other operations of the phone simultaneously.
For determining the frequency of the ringing tone, that is, the waveform, the user is able to program a ringing tone he/she desires by feeding in a numerical keyboard value to the phone. In addition, the user feeds other parameters to the phone to control the on/off configurations of the ringing tone. First, a "ringing tone programming" prefix is fed to the phone, followed by one or more values supplied by the user, on the basis whereof the ringing tone is determined.
Using the system disclosed in patent application GB-2,183,423 a plurality of different ringing tones can be generated, up to 2,176 different ringing tones. The system makes the use of the phone even more difficult than before because the phones, particularly mobile phones, include a great number of different operations and keys, so that the selection of a ringing tone by programming tends to make the use of the phone even more difficult, so that the user easily forgets how to use an operation because there are so many other things to remember, and it may occur that the programming of the ringing tone thus introduced is not used at all because it is forgotten or the user does not bother to learn how to do the programming.